Yellow triangle with an exclamation mark

Yellow triangle with an exclamation mark in it in my image list in the 1Ds panel.

It means that your camera (objective/chip size) has not been added to the software's database yet, which is a minor issue. If you can see a 35mm equivalent in the image info (either in the 1Ds or 2Ds panel), then it is all right. In case you do not see the 35mm equivalent there and you have the "focal length" in EXIF/XMP, then you can help RC to calculate the 35mm equivalent by adding a camera/lens model into its database. Adding this information will remove the yellow triangle.

What is a 35mm equivalent good for?

RC uses a 35mm equivalent as a soft prior during image registration/alignment. If the 35 mm focal is missing, it simply does not use the prior. This may cause problems if there is a lack of depth in the image/planar scene or camera undergoes a critical/close to a critical motion. Then the camera pose tends to be slightly off.

Do I need to add my camera information into the database?

It is not necessary to add every camera to the database. If a camera stores the 35 mm equivalent focal length into an image file, RC will read it from there. You should add a new entry if:

- your image files contain focal length other than 35mm equivalent, with respect to its chip size - lens distortion is directly noticeable in input images - adding priors helps registering images more precisely - a yellow question mark appears in the 1Ds panel next to an image when the system has incomplete camera information.

Where do I add a new camera model info?

Add a new line to the sensorsdb.xml file (located in the RC installation folder) with the camera model name, focal length (and camera distortion). Save changes and restart the program. For more information on the procedure of "Extending Camera Database" see the respective Help section built in your RC.

This is how these yellow triangles next to image names in the list of images in the 1Ds panel look like:

As we already know, the triangle is displayed because of the missing information on the camera focal length in RC's database. This can be fixed easily and fast by adding information about the camera ccd sensor width into the database. By clicking on an image name in the Images list (you can see this one when choosing the 1Ds view in the top right corner of the left layout window) the "Selected input(s)" information panel is displayed:

In the screenshot above we can see the camera model name: NIKON CORPORATION NIKON D90 (its image sensor size stated by manufacturer is 23.6 x 15.8 mm), which is currently missing in our database. We can access the sensor database through Program Data, in our case located on the (C:) drive.

The database is in an XML file format, which can be opened in any text editor. As we can see, the NIKON CORPORATION NIKON D90 camera is missing and needs to be added.

Here is our newly added line:

Now we need to save the XML, re-open the project in RealityCapture and the problem should be solved.

If you are not the computer administrator and you do not have the access to change the Program Data settings, first try to save the sensorsdb.xml file into another folder and then replace the former file with the new one.